21124000 has 48 divisors (see below), whose sum is σ = 51911496. Its totient is φ = 8448000.

The previous prime is 21123983. The next prime is 21124001. The reversal of 21124000 is 42112.

It can be written as a sum of positive squares in 4 ways, for example, as 2702736 + 18421264 = 1644^2 + 4292^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21124001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1360 + ... + 6640.

Almost surely, 2^21124000 is an apocalyptic number.

21124000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21124000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25955748).

21124000 is an abundant number, since it is smaller than the sum of its proper divisors (30787496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21124000 is an equidigital number, since it uses as much as digits as its factorization.

21124000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5306 (or 5288 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21124000 is about 4596.0852907665. The cubic root of 21124000 is about 276.4343786626.

Adding to 21124000 its reverse (42112), we get a palindrome (21166112).

The spelling of 21124000 in words is "twenty-one million, one hundred twenty-four thousand".